Alloys



Patented June 14, 1932 UNITED STATES ROBERT ABBOTT HADFIELD, OFWESTMINSTER, ENGLAND ALLOYS No Drawing. Application filed April 26,1928, Serial 273,156, and in France December 24, 1924.

This application, which is a continuation in part of in application forLetters Patent Serial No. 56,325, dated December 16th, 1924, hasreference to the production of alloys capable of oifering considerableresistance to corrosion by air, fresh water, salt water, and variousacids and other mediums that attack ordinary iron or steel, and whichshall also possess good mechanical characteristics, including hightensile and compression strength and ductility.

Various alloys have heretofore been proposed possessing thesecharacteristics in various degrees and the present invention has for itsobject to produce alloys possessing the said characteristics in anenhanced degree, whereby they are rendered available for variousindustrial purposes.

For this purpose, an alloy according to the present invention,comprises, in addition to iron, from about 0.05 to 1% of carbon, fromabout 6 to 25% of chromium, from about 5 upward but less than 20% ofnickel, from about 1 to 5% of tungsten, from about 1 to 3% of copper,from about 0.05 to 1% of silicon and from about 0.10 to 4% of manganese,the combined chromium and nickel content being in all cases from 18 to32%. The percentage of the various elements contained in such an alloyma vary within the limits mentioned to suit di erent purposes for whichthe alloy is to be used.

The following are analyses of some examples of the alloys that have beenfound, by experiment, to offer excellent resistance to corrosion byacids, both hot and cold, and to other chemicals, for instance asolution of ammonic chloride, and which moreover possess considerablestrength and toughness and are capable of being readily worked toconvert them into articles of different shapes to adapt them for use inindustries of various kinds.

1. Iron, with carbon about 0.20%, nickel about 10.2%, chromium about16.1%, tungsten about 1.37% and copper about 2%, with about 0.35% ofsilicon and about 0.39% of manganese.

2. Iron, with carbon about 0.22%, nickel about 7.3%, chromium about16.2%, tungsten about 1.87% and copper about 1.90%, with about 0.28% ofsilicon and about 0.10% of balt, vanadium, titanium oraluminium, or

'two or more of such elements, usually in small percentages, say fromabout 0.5 up to 6%, may, in some cases, also be included in alloysaccording to the present invention for improving their qualities incertain respects to meet special requirements.

As molybdenum is the equivalent of tungsten in its power of impartingthe above mentioned characteristics to the alloy, it is to be understoodthat this element is included in the term tungsten in the appendedclaims.

What I claim is I 1. An alloy comprising, in addition to iron, fromabout 0.05 to 1% of carbon, from about 6 to 25% of chromium, from about5% upward but less than 20% of nickel, from 1 to 5% tungsten, from 1 to3% of cop er, from about 0.05 to 1% silicon and from a out 0.10 to 1% ofmanganese, the combined chromium and nickel content being from 18 to32%.

' 2. An alloy comprising about 0.20% carbon, about 0.35% silicon, about0.39% manganese, about 10.2% nickel, about 16.1% chromium, about 1.37%tungsten and about 2% copper, the remainder being principally iron.

3. An alloy comprising about 0.06% carbon, about 0.14% silicon, about0.52% manganese, about 19.8% nickel, about 10.1% chromium, about 1.94%tungsten and about 1.81% copper, the remainder being principally iron.

4. An alloy comprising about 0.22% carbon, about 7.3% nickel, about16.2% chromium, about 1.87% tungsten, about 1.9% copper, about 0.28%silicon and about 0.10% manganese.

Signed at the city of London, this third day of April, 1928.

ROBERT ABBOTT HADFIELD.

England,

